I'd say go with the 1201 M simply because you have the 1203. The M will throw 1 oz plugs ok but it won't load and really toss em out there of course jigs,
tins, needles and pencils are another story they almost always toss well. Like Jim stated the M has plenty of backbone for big fish in boneyards and areas with plenty of structure.
The L is a sweet blank also. More than capable of handling any big fish and tossing up to a smidge over 3 but is more suited to open beaches or areas with slight structure.